Descriptions

A Right-hook (RH) crash is a common type of bicycle-motor vehicle crash that occurs between a right-turning vehicle and through-moving bicycle at an intersection. At signalized intersections, RH crashes can occur at the onset of the green or during the latter portion of the green phase. In spite of the frequency and severity of this crash type, no experimental studies have provided compelling evidence as to the root causes of RH crashes at signalized intersections. This research provided improved understanding of RH crash causal factors during the latter portion of the green phase through an online survey and driving simulator experiment. From the 209 self-reported online survey responses, it was found that 78% of bicyclists were unaware of their stopping position with respect to stopped vehicles queued at an intersection during a red indication, and 19% of motorists (n = 246) reported that they would not yield to the adjacent bicyclist approaching from behind if they were detected in rear-view or side-view mirrors. The driving simulator experiment (n = 51) investigated RH crash causal factors related to the motorist and built environment using three different motorist performance measures: i) visual attention, ii)
situation awareness (SA) and iii) crash avoidance behavior. Motorist’s visual attention measure revealed that in the presence of oncoming vehicular traffic, motorists spent the majority of their visual attention looking at the oncoming traffic that posed immediate hazard to them and failed to detect a bicyclist approaching from behind. Motorists' SA measure indicated that motorists detect a bicyclist riding in their forward field of view more successfully than a bicyclist approaching from behind in the vehicle's blind spot. Motorist's crash avoidance behavior revealed that 92% of 26 observed crashes occurred with a bicyclist approaching from behind in the vehicle's blind spot and oncoming vehicles were present in 88% of those crashes. Also, 81% of observed crashes occurred due to inadequate surveillance.